Cosabella

Hanging out with a pal in the SoHo section of New York City, Jessica Biel popped into Cosabella lingerie boutique over the weekend.

"She didn't come into the store looking for anything in particular, but she purchased an assortment of bottoms," a source tells PEOPLE, explaining that she left with g-strings, thongs and low-rider bikini undies.

"She was super nice and couldn't have been sweeter to the staff," the source says, adding that she chatted with fiancéJustin Timberlake on her cell phone while she was in the store. "She was ridiculously gorgeous in person." – Jennifer Cress